Audiologic Findings in Unilateral Deafness from Contralateral Pontine
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The Superior and Inferior Colliculi of the Mole (Scalopus Aquaticus Machxinus)
THE SUPERIOR AND INFERIOR COLLICULI OF THE MOLE (SCALOPUS AQUATICUS MACHXINUS) THOMAS N. JOHNSON' Laboratory of Comparative Neurology, Departmmt of Amtomy, Un&versity of hfiehigan, Ann Arbor INTRODUCTION This investigation is a study of the afferent and efferent connections of the tectum of the midbrain in the mole (Scalo- pus aquaticus machrinus). An attempt is made to correlate these findings with the known habits of the animal. A subterranean animal of the middle western portion of the United States, Scalopus aquaticus machrinus is the largest of the genus Scalopus and its habits have been more thor- oughly studied than those of others of this genus according to Jackson ('15) and Hamilton ('43). This animal prefers a well-drained, loose soil. It usually frequents open fields and pastures but also is found in thin woods and meadows. Following a rain, new superficial burrows just below the surface of the ground are pushed in all directions to facili- tate the capture of worms and other soil life. Ten inches or more below the surface the regular permanent highway is constructed; the mole retreats here during long periods of dry weather or when frost is in the ground. The principal food is earthworms although, under some circumstances, larvae and adult insects are the more usual fare. It has been demonstrated conclusively that, under normal conditions, moles will eat vegetable matter. It seems not improbable that they may take considerable quantities of it at times. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the University of Michigan. -
Neuronal Organization in the Inferior Colliculus Revisited with Cell-Type- Dependent Monosynaptic Tracing
This Accepted Manuscript has not been copyedited and formatted. The final version may differ from this version. Research Articles: Systems/Circuits Neuronal organization in the inferior colliculus revisited with cell-type- dependent monosynaptic tracing Chenggang Chen1, Mingxiu Cheng1,2, Tetsufumi Ito3 and Sen Song1 1Tsinghua Laboratory of Brain and Intelligence (THBI) and Department of Biomedical Engineering, Beijing Innovation Center for Future Chip, Center for Brain-Inspired Computing Research, McGovern Institute for Brain Research, Tsinghua University, Beijing, 100084, China 2National Institute of Biological Sciences, Beijing, 102206, China 3Anatomy II, School of Medicine, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan DOI: 10.1523/JNEUROSCI.2173-17.2018 Received: 31 July 2017 Revised: 2 February 2018 Accepted: 7 February 2018 Published: 24 February 2018 Author contributions: C.C., T.I., and S.S. designed research; C.C. and M.C. performed research; C.C. and T.I. analyzed data; C.C. wrote the first draft of the paper; C.C., T.I., and S.S. edited the paper; C.C., T.I., and S.S. wrote the paper. Conflict of Interest: The authors declare no competing financial interests. This work was supported by funding from the National Natural Science Foundation of China (31571095, 91332122, for S.S.), Special Fund of Suzhou-Tsinghua Innovation Leading Action (for S.S.), Beijing Program on the Study of Brain-Inspired Computing System and Related Core Technologies (for S.S.), Beijing Innovation Center for Future Chip (for S.S.), and Chinese Academy of Sciences Institute of Psychology Key Laboratory of Mental Health Open Research Grant (KLMH2012K02, for S.S.), grants from Ministry of Education, Science, and Culture of Japan (KAKENHI grant, Grant numbers 16K07026 and 16H01501; for T.I.), and Takahashi Industrial and Economic Research Foundation (for T.I.). -
DR. Sanaa Alshaarawy
By DR. Sanaa Alshaarawy 1 By the end of the lecture, students will be able to : Distinguish the internal structure of the components of the brain stem in different levels and the specific criteria of each level. 1. Medulla oblongata (closed, mid and open medulla) 2. Pons (caudal, mid “Trigeminal level” and rostral). 3. Mid brain ( superior and inferior colliculi). Describe the Reticular formation (structure, function and pathway) being an important content of the brain stem. 2 1. Traversed by the Central Canal. Motor Decussation*. Spinal Nucleus of Trigeminal (Trigeminal sensory nucleus)* : ➢ It is a larger sensory T.S of Caudal part of M.O. nucleus. ➢ It is the brain stem continuation of the Substantia Gelatinosa of spinal cord 3 The Nucleus Extends : Through the whole length of the brain stem and upper segments of spinal cord. It lies in all levels of M.O, medial to the spinal tract of the trigeminal. It receives pain and temperature from face, forehead. Its tract present in all levels of M.O. is formed of descending fibers that terminate in the trigeminal nucleus. 4 It is Motor Decussation. Formed by pyramidal fibers, (75-90%) cross to the opposite side They descend in the Decuss- = crossing lateral white column of the spinal cord as the lateral corticospinal tract. The uncrossed fibers form the ventral corticospinal tract. 5 Traversed by Central Canal. Larger size Gracile & Cuneate nuclei, concerned with proprioceptive deep sensations of the body. Axons of Gracile & Cuneate nuclei form the internal arcuate fibers; decussating forming Sensory Decussation. Pyramids are prominent ventrally. 6 Formed by the crossed internal arcuate fibers Medial Leminiscus: Composed of the ascending internal arcuate fibers after their crossing. -
Auditory and Vestibular Systems Objective • to Learn the Functional
Auditory and Vestibular Systems Objective • To learn the functional organization of the auditory and vestibular systems • To understand how one can use changes in auditory function following injury to localize the site of a lesion • To begin to learn the vestibular pathways, as a prelude to studying motor pathways controlling balance in a later lab. Ch 7 Key Figs: 7-1; 7-2; 7-4; 7-5 Clinical Case #2 Hearing loss and dizziness; CC4-1 Self evaluation • Be able to identify all structures listed in key terms and describe briefly their principal functions • Use neuroanatomy on the web to test your understanding ************************************************************************************** List of media F-5 Vestibular efferent connections The first order neurons of the vestibular system are bipolar cells whose cell bodies are located in the vestibular ganglion in the internal ear (NTA Fig. 7-3). The distal processes of these cells contact the receptor hair cells located within the ampulae of the semicircular canals and the utricle and saccule. The central processes of the bipolar cells constitute the vestibular portion of the vestibulocochlear (VIIIth cranial) nerve. Most of these primary vestibular afferents enter the ipsilateral brain stem inferior to the inferior cerebellar peduncle to terminate in the vestibular nuclear complex, which is located in the medulla and caudal pons. The vestibular nuclear complex (NTA Figs, 7-2, 7-3), which lies in the floor of the fourth ventricle, contains four nuclei: 1) the superior vestibular nucleus; 2) the inferior vestibular nucleus; 3) the lateral vestibular nucleus; and 4) the medial vestibular nucleus. Vestibular nuclei give rise to secondary fibers that project to the cerebellum, certain motor cranial nerve nuclei, the reticular formation, all spinal levels, and the thalamus. -
ON-LINE FIG 1. Selected Images of the Caudal Midbrain (Upper Row
ON-LINE FIG 1. Selected images of the caudal midbrain (upper row) and middle pons (lower row) from 4 of 13 total postmortem brains illustrate excellent anatomic contrast reproducibility across individual datasets. Subtle variations are present. Note differences in the shape of cerebral peduncles (24), decussation of superior cerebellar peduncles (25), and spinothalamic tract (12) in the midbrain of subject D (top right). These can be attributed to individual anatomic variation, some mild distortion of the brain stem during procurement at postmortem examination, and/or differences in the axial imaging plane not easily discernable during its prescription parallel to the anterior/posterior commissure plane. The numbers in parentheses in the on-line legends refer to structures in the On-line Table. AJNR Am J Neuroradiol ●:●●2019 www.ajnr.org E1 ON-LINE FIG 3. Demonstration of the dentatorubrothalamic tract within the superior cerebellar peduncle (asterisk) and rostral brain stem. A, Axial caudal midbrain image angled 10° anterosuperior to posteroinferior relative to the ACPC plane demonstrates the tract traveling the midbrain to reach the decussation (25). B, Coronal oblique image that is perpendicular to the long axis of the hippocam- pus (structure not shown) at the level of the ventral superior cerebel- lar decussation shows a component of the dentatorubrothalamic tract arising from the cerebellar dentate nucleus (63), ascending via the superior cerebellar peduncle to the decussation (25), and then enveloping the contralateral red nucleus (3). C, Parasagittal image shows the relatively long anteroposterior dimension of this tract, which becomes less compact and distinct as it ascends toward the thalamus. ON-LINE FIG 2. -
(12) United States Patent (10) Patent No.: US 9,358,393 B1 L0zano (45) Date of Patent: Jun
US00935.8393B1 (12) United States Patent (10) Patent No.: US 9,358,393 B1 L0ZanO (45) Date of Patent: Jun. 7, 2016 (54) STIMULATION METHODS AND SYSTEMS 4,203,440 A 5/1980 Theeuwes FORTREATING AN AUDITORY 4,203.442 A 5/1980 Michaels DYSFUNCTION 4,210,139 A 7/1980 Higuchi (Continued) (76) Inventor: Andres M. Lozano, Toronto (CA) FOREIGN PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 WO WOO1,08617 A1 2/2001 U.S.C. 154(b) by 1826 days. OTHER PUBLICATIONS (21) Appl. No.: 11/271,126 Office action dated Sep. 16, 2009 for related U.S. Appl. No. 1 1/271,688 (Lozano-1), filed Nov. 9, 2005, Inventor: Andres M. (22) Filed: Nov. 9, 2005 Lozano, (14 pages). Related U.S. Application Data (Continued) (60) gynal application No. 60/626,174, filed on Nov. Primary Examiner — Nicole F Lavert s (74) Attorney, Agent, or Firm — Faegre Baker Daniels LLP (51) Int. Cl. A61N L/00 (2006.01) (57) ABSTRACT A6 IB5/02 (2006.01) Methods of treating auditory hallucinations, hyperacusis, A6 IN L/36 (2006.01) Schizophrenia, and/or phonophobia include applying at least A61N L/05 (2006.01) one stimulus to a stimulation site within a patient with an (52) U.S. Cl. implanted stimulator in accordance with one or more stimu CPC .......... A61N I/36132 (2013.01); A61N I/0541 lation parameters. The stimulation site may include, for (2013.01) example, at least one or more of a cochlear nucleus, auditory (58) Field of Classification Search striae, Superior olivary complex, lateral lemniscus, inferior USPC ...................................... -
Synaptics and the Auditory Nerve;.Pdf
Salamanca Study Abroad Program: Neurobiology of Hearing Synaptics and the auditory nerve R. Keith Duncan University of Michigan [email protected] Review Resources Reviews: Safieddine et al., 2012, The auditory hair cell ribbon synapse: From assembly to function, Ann Rev Neurosci, 35:509-528 Kim et al., 2013, Single Ca2+ channels and exocytosis at sensory synapses, J Physiol, epub Note: this is an excellent review describing the differences between cochlear and retinal ribbon synapses. Rabbitt and Brownell, 2011 Efferent modulation of hair cell function, Curr Opinion Otolaryngol Head Neck Surg,19:376-381 Outline Exocytosis and synaptics Afferent physiology Efferent physiology Afferent cochlear innervation Type 1 afferents: • 95% of cochlear afferents • account for hearing • each innervates only 1 IHC • ~20 innervate one IHC Type 2 afferents: • less well-described • en passant innervation of OHCs; 4 Hair cells form ribbon synapses with afferent neurons 5 Distinct pools of vesicles • Electron tomography reconstruction shows 4 pools Ribbon docked vesicles (readily releasable pool, ~10) Tethered vesicles (releasable pool, ~200) Extrasynaptic docked vesicles Cytoplasmic vesicles (recruitable pool?) • These pools likely contribute to distinct kinetics of exocytosis as Lenzi & von Gersdorff, 2001 stimulus duration increases. Distinct phases of exocytosis Capacitance is a proxy for exocytosis. Vesicle fusion increases surface area which increases capacitance. (see supplemental slides) Exocytosis occurs in calcium nanodomains Hair cells The synaptic vesicle cycle NT uptake, translocation, docking Molecular Components of Ribbon Synapses Differ from Conventional Synapses Vesicle related: • Synaptotagmins are the Ca2+ sensors in most synapses. Mature hair cells lack SYT I and II but have IV, VI-IX (rare types). -
Commissural Projections of the Nuclei of the Lateral Lemniscus and Keuronal Degeneration Following Midline Transections in the Adult Rat By
Commissural Projections of the Nuclei of the Lateral Lemniscus and Keuronal Degeneration Following Midline Transections in the Adult Rat by Brian Anthony van Adel B .Sc. (Hons) Carleton University, 1995 A thesis subrnitted to the faculty of Graduate Studies and Research in partial fulnllment of the requirements of the degree of Master of Science Specialization in Neuroscience Deparûnent of Biology Ottawa-Carleton Institutes of Biology and Neuroscience Carleton University Ottawa, Ontano May, 1998 O copyright 1998, Brian Anthony van Adel National Library Bibliothèque nationale 1+1 .,nad, du Canada Acquisitions and Acquisitions et Bibliographie Services seMces bibliographiques 395 Wellington Street 395, rue Wellington OttawaON KtAW ûuawaON KtAON4 canada CaMda The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, 10- disûiiute or sen reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette these sous paper or electronic formats. la forme de microfiche/fïlm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fiom it Ni la thèse ni des extraits substantiels may be printed or otheMrise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. ABSTRACT The normal neuroanatomical organization of the rat's nuclei of the lateral lemniscus (nLL) was investigated (Experiment 1) as a prerequisite for a time course analysis of retrograde changes in commissural projec~glemniscd neurons following midline surgical transection of their axons (Expriment 2). -
NIH Public Access Author Manuscript Curr Opin Otolaryngol Head Neck Surg
NIH Public Access Author Manuscript Curr Opin Otolaryngol Head Neck Surg. Author manuscript; available in PMC 2012 October 01. NIH-PA Author ManuscriptPublished NIH-PA Author Manuscript in final edited NIH-PA Author Manuscript form as: Curr Opin Otolaryngol Head Neck Surg. 2011 October ; 19(5): 376–381. doi:10.1097/MOO. 0b013e32834a5be1. EFFERENT MODULATION OF HAIR CELL FUNCTION RICHARD D. RABBITT1,2 and WILLIAM E. BROWNELL3 1Department of Bioengineering, University of Utah, Salt Lake City, UT, USA 2Marine Biological Laboratory, Woods Hole, MA, USA 3Department of Otolaryngology, Head and Neck Surgery, Baylor College of Medicine, Houston, TX, USA Abstract Purpose of review—This review covers papers published between 2010 and early 2011 that presented new findings on inner ear-efferents and their ability to modulate hair cell function. Recent findings—Studies published within the review period have increased our understanding of efferent mechanisms on hair cells in the cochlear and vestibular sensory epithelium and provide insights on efferent contributions to the plasticity of bilateral auditory processing. The central nervous system controls the sensitivity of hair cells to physiological stimuli by regulating the gain of hair cell electromechanical amplification and modulating the efficiency of hair cell-8th nerve transmission. A notable advance in the past year has been animal and human studies that have examined the contribution of the olivocochlear efferents to sound localization particularly in a noisy environment. Summary—Acoustic activation of olivocochlear fibers provides a clinical test for the integrity of the peripheral auditory system and has provided new understanding about the function and limitations of the cochlear amplifier. -
The Nuclear Pattern of the Nok-Tectal Portions of the Midbrain and Isthmus in the Opossum
THE NUCLEAR PATTERN OF THE NOK-TECTAL PORTIONS OF THE MIDBRAIN AND ISTHMUS IN THE OPOSSUM RUSSELL T. WOODBURNE Department of Anatomy, Uniwersity of Yichigan SIX PLATES (TWELVE FIGURES) INTRODUCTION It is logical that the present series of descriptions of the nuclear pattern of the midbrain tegmentum in mammals should begin with the account of this region in marsupials, since the American opossum presents a simplified and generalized type of mammalian midbrain. The material employed in the present study consists of toluidin blue series, cut in various planes, of the brain of the American opossum, Didelphis virginiana. These preparations are a part of the Huber Neurological Collection of the Department of Anatomy of the University of Michigan. The literature particularly pertinent to specific nuclear de- scriptions will be discussed in connection with such descrip- tions and the general literature dealing with other than marsupial forms is dealt with in other sections of this series of papers and complete reference made in the comprehensive bibliography. There are, however, certain papers of which some mention should be made. The series of papers by Castaldi ('23, '24, '26) gave the basis for the nomenclature and the general pattern of subdivision followed here. Tsai's ('25) account of portions of the marsupial midbrain, although con- cerned primarily with tectal and pretectal areas, gave some aid in orientation. Certain of the pretectal regions were con- sidered in the light of earlier accounts of Chu ( '32) and Bodian ('40). The text of Ariens Kappers, Huber and Crosby ('36) was used for general orientation and comparative information. -
A. Diencephalon B. Telencephalon C. Metencephalon D
SAMPLE TEST QUESTIONS Select the one best answer. l. The olfactory nerve is attached to the: A. Diencephalon B. Telencephalon C. Metencephalon D. Mesencephalon E. Myelencephalon 2. Following complete transection of a peripheral nerve, all the following may occur except: A. Chromatoloysis in the cell body. B. Degeneration of peripheral myelin distal to the site of injury. C. Degeneration of the axon distal to the site of injury. D. Immediate restoration of normal function following prompt surgical repair. E. Outgrowth of axonal sprouting from the proximal nerve stump .. 3. A lesion of the left hypoglossal nerve causes: A. Loss of taste sensation on the left side of the tongue. B. Deviation of the tongue to the right side, upon protrusion. C. Total inability to protrude the tongue. D. Deviation of the tongue to the left, upon protrusion. E. Hoarseness. 4. In the brain stem, the principle sensory decussation f0r general sensation ca~ried in the posterior columns of the spinal cord forms the: A. Medial lemniscus. B. Lateral lemniscus. C. Central tegmental fasciculus D. Medial longitudinal fasciculus E. Spinal lemniscus. 5. All are true of the lateral spinothalamic tract except: A. It caries sensations of pain and thermal sense. B. Fibers from sacral origin are located in the ventro-medial portion of the tract. C. Decussation occurs within one or two spinal segments of its origin. D. Fibers of cervical origin are located in the ventro-medial portion of the tract. E. It forms part of the brain stem lemniscal systems. 81 6. A unilateral lesion of the internal capsule involving the genu and the posterior limb, would cause: A. -
Cholinergic Top-Down Influences on the Auditory Brainstem
Neuroforum 2017; 23(1): A35–A44 Thomas Künzel* and Hermann Wagner Cholinergic top-down influences on the auditory brainstem DOI 10.1515/nf-2016-A107 Sensory pathways are often mistakenly seen as purely ascending streams of information, where a given neuron Abstract: Descending connections are present in many feeds information only “upwards” to stations of increas- sensory systems and support adaptive information pro- ing complexity in a higher hierarchical level. In a well- cessing. This allows the sensory brain to code a wider known example, time-coding neurons in the cochlear range of inputs. A well characterized descending system nucleus are contacted by giant synaptic terminals of the is the olivo-cochlear cholinergic innervation of the inner auditory nerve (Felmy and Künzel, 2014) and pass infor- ear, which mediates a reduction of the sensitivity of the mation about the timing of the perceived sound up along inner ear upon perception of intense sounds. Because this the auditory pathway into binaural nuclei with more com- inhibits the response to background noise, the olivo-coch- plex functions. These neurons are clearly dominated by lear system supports detection of transient sound events. information flow from hierarchically lower to higher sta- Olivo-cochlear neurons also innervate the cochlear nucle- tions, as the ascending synaptic connection from the au- us through axon collaterals. Here, acetylcholine increases ditory nerve onto the time-coding neuron is very powerful. the excitability of central neurons without reducing their Although it is well established that the auditory periphery temporal precision. Thus their target neurons in the supe- and the first stages of the auditory pathway indeed show rior olivary complex can more effectively process binau- activity dependent dynamics, these adaptive phenomena ral temporal cues.